Grinding-mill disk.



M. R. MARTIN.

GRINDING MILL DISK. APPLICATION FILED I'uLvzz. 191s.

Patented 11111613, 1916.

OFFICE.

MYRON R. MARTIN, OF ST. LOUIS PARK, MINNESOTA.

GRINDING-MILL DISK.

specincation of Letters Patent.

Patented June is, 1ere.

Application led .Tuly 22, 1915. Serial No. 41,345.

To all whom t may concern:

Be it known that I, MYRON R. MARTIN, citizen of the United States, residing at St. Louis Park, Minnesota, have invented certain new and useful Improvements in Grinding-Mill Disks, of which the following is a specification.

My invention relates: to grinding milil disks for use in grinding materials of various characters, such as grain, or grain on the cob, and the cob itself, and the invention relates particularly to the grinding burs or disks.

The invention is shown in the accompanying drawings, in which- Figure l is a face View of the stationary grindin bur or disk, this view showing in dotted lines the relation of the teeth or ribs on the rotary member or bur; Fig. 2 is a sectional view of the bur substantially on the line a-a of Fig. l; and Fig. 2a is an edge view of part of the bur. Figs. 3 and 4 are views of modified forms of the surface 'of the bur.

The grinding face of the disk is made up of a series of cast ribs 5 each extending in a general direction at an acute angle to the radius of the disk. These ribs are shown as slightly curved and they diverge from each other outwardly. They extend from the inner edge of the ring at the central eye or opening 6 to the outer edge, and they have teeth 7 along one side. These ribs are arranged in sets consisting of a long rib at a and shorter ribs at b, c, el, e and f, these ribs being progressively shorter, and by reason of this channels or spaces are left at 8 for the passage of the grain or other material being ground outwardly from the eye of the bur toward its periphery. This space 8 has its bottom wall curved, as shown in Fig. 2, this resulting from thinning the thickness of the bur toward the inner edge thereof at said point or space 8. The rotary bur is mounted on the same shaft which carries the conveyer 3, and its surface is similarly formed to that of the fixed bur, but being placed face to face with said fixed bur its ribs incline in the reverse direction from those of the fixed bur, or in other words, cross the same at a sharp angle, as shown in dotted lines at a', o', c.

It will now be observed that when the rotary bur is moved in the direction of the arrow the teeth on the lateral sides Q the ribs of said movable bur facing toward the left 1n Fig. 1 will coperate with the teeth on the ribs of the fixed bur which face toward the rightin said figure, and the grain or. other material caught between these teeth Wll'l be cracked, broken up and finely ground as 1t passes from the eye of the bur toward the periphery. The long ribs a are substantlally the same height throughout, whereas the other ribs b, 0, cl, c, f, are tapered downwardly or toward the opposite side of the disk or bur from about the point m, thus prov lding space for the passage of the material to the grinding surfaces which are parallel with each other at about the point y, Fig. 2.

In Figs. 3 and 4 I show modified forms of the bur surfaces, in the figure first mentioned the teeth, instead of being of the angular shape of Fig. l, being curved, whereas in Fig. 4 the teeth have straight sides which are of substantially equal length, whereas in Fig. 1 the teeth present more of a shouldered construction, that is, they have one long side and one short side.

By using the ribs with the lateral teeth I gain a greater output over any form of bur in which plain untoothed ribs are employed because the reduction process begins as soon as a grain is caught between the teeth of the opposed disks and the spaces between the ribs may be of greater width than in the case of plain ribs because there is no danger of a grain passing through the channel without being broken up by the teeth. In the' forms used heretofore with plain ribs 1t is necessary to keep the ribs close together to prevent the grain from going through in unbroken condition, and thus the passage of the mass is retarded, and its volume at the discharge reduced. Further, by using the Y teeth on the side of the rib instead of the top the grains are crowded against these teeth and are rapidly ground. Again the bur can be readily ground or shaped by simply applying its face to an emery or other grinding wheel which acts on the tops of the ribs and as it were grinds the face of the disk down to the desired plane, and they can be repeatedly resharpenedand will thus outlast burs of the old constructions.

I claim as my invention A rinding disk having ribs cast on its face 1n a plurality of groups, each group comprising a series made up of successively shorter ribs leaving a free space between one group and the next group adjacent the center opening, said space having its bottom Wall inclined up from the edge of the opening, each of said cast ribs extending at an angle to the radii of the disk and each having a flat top face and having one edge serrated and the opposite edge plain, the said plein edges diverging in respect to the opposing serrated edges toward the outer edge 10 of the disk, substantially as described.

In testimony whereof, I affix my signuture.

MYRON R. MARTIN.

Gopie of this patent may be obtained for ve cents each, by addressing the Commissioner of Patente washington, n. c. 

